var quickSort=function(arr){
    if(arr.length<1){
        return arr;
    }
    let pivotIndex=Math.floor(arr.length/2);
    let pivot=arr.splice(pivotIndex,1)[0];
    let left=[];
    let right=[];
    for(let i=0;i<arr.length;i++){
        if(arr[i]<pivot){
            left.push(arr[i]);
        }
        else{
            right.push(arr[i]);
        }
    }
    return quickSort(left).concat([pivot],quickSort(right));
}